Method and means for conditioning fuel for internal combustion engines



Aug; 30, 1932.

R. F. BRACKE METHOD AND MEANS FOR CONDITIONING FUEL FOR INTERNALCOMBUSTION ENGINES Filed Aug. 13, 1927 'llIIIIIIIII/IIIIIIIIII/JIlflllllf! I Illlllrlllllllllll/ liliiiilllli' j? csz frzzrerz forPatented Aug. 30, 1932 UNITED STATES PATENT OFFICE ROBERT I. BIB-ACRE,OF CHICAGO, ILLINOIS, ASSIGNOR TO CURTIS 3. CW, TRUSTEE, OF GLENCOE,ILLINOIS 'KETHOD AND MEAN S FOB CONDITIONING FUEL FOR INTERNALCOMBUSTION ENGINES Application filed August 18, 1927. Serial 1T0.212,685.

means of the character described, in which no appreciable decrease inthe weight of the fuel charge is brought about by the application ofheat suflicient for complete vaporization of the fuel.

A further object is to provide a method and means in which thecarburetor may be quickly warmed up for eflicient operation.

A further object is to provide apparatus for conditioning fuel forinternal combus tion engines, which is simple and inexpensive inconstruction, but which affords most favorable operating condition ofthe carburetor, including economy at part throttle without the sacrificeof power at open throttle. The

use of the ordinary type of hot spot for heating the air intake to thecarburetor so great 1y decreases the weight of the charge for a givenvolume in an effort to bring about readyvaporization of the fuel thatthe expansive property of the fuel admitted to the manifold is reducedand therefore power is sacrificed.

A further object of the invention is to provide a. method and means ofthe character described in which the degree to which the fuel may beheated is under control of the driver from a point on the instrumentboard of the vehicle.

Other objects and advantages will be more particularly pointed out inthe following specification and claims.

The invention as illustrated in the accompanying drawing forms a part ofthis application, in which:

Fig. 1 is a sectional view of a carburetor and engine manifold embodyingmy invention.

Fig, 2 is a sectional view throu h the in strument board of the vehicleil ustrating the manual control of the heater and 'Fig. 3 is afragmentary view, partly in section, of a modified form of theinvention.

In carrying out the invention I make use of an internal combustionengine having an intake manifold 10 and an exhaust manifold 11. Thecarburetor A has a fuel delivery passage 12 which is connected with theintake manifold 10 of the engine.

The carburetor A has a primary induction passage 13 in the form of aVenturi tube which projects through a side wall of the induction chamber14 of the carburetor.

Fuel is drawn to the throat 15 of the primary air passage 13 by virtueof the suction multiplying principles of the Venturi from a fuel chamber16 which communicates through a valve 17 operated by atmosphericpressure to the fuel supply tank of the vehicle. In a carburetor of thistype throughout the entire operating range of the carburetor suflicientdepression is maintained in the fuel chamber 16 to lift fuel theretofrom a low level supply tank, utilizing therefore, only that smallproportion of the amount of air admitted to the induction chamber whichflows through the primary air passage 13. The major ortion of airadmitted to the chamber is a 'tted through the secondary air passage 18.

It is the passage 18 which in ordinary devices receives pre-heated airto assist in conditioning fuel for carburetion that is connected with ahot air source.

The means which I employ for conditioning the fuel unlike the presentmeans, consists in conducting warm air from a jacket 19 disposed aboutthe exhaust manifold 11 tothe -intake orifice of the primary inductionpassage 13. This is done by means of a tube 20 communicating with theintake orifice of the passage at one end and with a valve chamber 21 atits opposite end, which is also connected with the jacket 19.

, A valve 22 is disposed within the chamber 1 21 which is operated bymeans of an arm 23 disposed exteriorly of the chamber and connected to arod 24, the other end of which is secured to a hand-grip 25 carried bysuitable supporting means 26 on the instrument board 27 of the vehicle.Longitudinal oscillation of the hand-grip 25 will cause proportionatemovement of the valve 22. l

That end of the valve chamber 21 opposite to its intake opening 28'whichcommunicates with the jacket 19 has an opening 29 communieating with theatmosphere.

The position of the valve 22 in the chamber 21 therefore determines theamount of'warm air and air at normal temperature which is admitted tothe primary air passage 13 so that the temperature of the in-flowingstreammay be controlled at will by actuation of the control 25.

For-warming up the engine the valve 22 is actuated by means of thehand-grip 25 so as to assume the position .shown in full lines inFig. 1. Thus operation ofthe engine and the heating of the manifold 11from exhaust gases, supplies only warm air to the primary passage 13,due to the fact that openin 29 in valve chamber 21 is closed. Thus t eair stream primarily uniting with fuel admitted through the throat 15 ofthe primary air passage materially increases the tendency of the fuel tovaporize as it is {emitted from the primary air passage into inductionchamber 14. The vaporized fuel in chamber 14 is united with air atnormal temperature which is drawn into secondary air passage 18 and themixture passes up through passage 12 into the intake manifold. Thecharge is properly conditioned for initial operation of the engine sincethe warm air first admitted to the fuel delivered into chamber 14 hascaused' suflicient vaporizing of the fuel to render it in the propercondition for combustion.

This method of pre-heating only a part of the air stream, being thatpart which primarily is united with the fuel, does not appreciablydecrease the weight of the char e so as to sacrifice power as wouldnecessari y have to occur if all the air admitted to the carburetor washeated sufliciently to cause the fuel to readily vaporize.

After the engine has been running and the carburetor body has becomeheated by radiation, the valve 22 is moved by actuati'on of thehand-grip 25 upon the instrument board so as to feed some air throughopening 29 at normal temperature. This reduces the temperature of theair passing through the primary' air passage'13 to compensate for thethen warmer air admitted through the passa e 18.

y employing this method and apparatus for conditioning the fuel, Ieliminate the necessity of using excessive chokes and the like whichtend to throw raw fuel into the cylinders of the engine and cause crankcase dilution as well as other numerous disad vantages.

In Fig. 3 I have shown a modification of the means for warming airadmitted to valve chamber 21. In this form of the invention I project atube diametrically through the exhaust manifold 11. connecting oneend'to intake opening 28 of valve 21 and the opposite end communicateswith the atmosphere at the opposite side of the manifold 11. This meansfor heating the air does not depend upon first warming the exhaustmanifold 11 but instead receives heat directly from the passage of hotexhaust gases through the manifold even prior to the warming of themanifold.

What I claim is:

1. The combination with a carburetor having a relatively small primaryair passage and a relatively large secondary air passage, means forinjecting fuel to said carburetor through said primary air passage, saidmeans admitting said fuel to the primary air passage at normaltemperature, and adjustable means for admitting warm air to said primaryair passage prior to the admission of fuel thereto to hasten thevaporization of fuel in-jectedtherethrough.

2. The combination with a carburetor having a relatively small primaryair passage communicating with the induction chamber of the carburetorand a relatively large secondary air passage communicating with saidchamber, means for injecting fuel to said primary'air passa e at a pointadjacent to the induction cham 'r and at normal temperature, means forwarming the air admitted through said primary air passage at a' pointprior to its contact with the fuel admitted thereto, an inductionchamber communicating with said secondary air passage, and means foradmitting heated air and fuel into said induction chamber as across-current to the stream of air flowing through said inductionchamber from said secondary air passage.

3. The combination with the carburetor having a primary and secondaryair passage, said secondary air passage being greater in diameter thanthe primary air passage, means for heating air admitted to the primaryair passage, means for injecting fuel at normal temperature into thewarm air stream passing through said primary air passage, an inductionchamber, and means for admitting air and fuel from said primary airpassage into said induction chamber at an angle to the axis thereof. I

. 4. The combination with a carburetor having an induction chamber and aprimary and secondary alr passage, said secondary air passage beinggreater'in diameter than the; primary air passage, means for heating airada point adjacent to the delivery orifice of the primary air passage.

5. The method of conditioning fuel for internal combustion engines,which consists in admitting warmed air to the induction chamber of acarburetor at an angle to the axis thereof and in injecting fuel atnormal temperature into the warm air stream at a point immediatelyadjacent to the induction chamber.

6. The method of conditioning fuel for internal combustion engines,which consists in supplying a relatively large quantity of air at normaltemperature to the induction chamber of the carburetor at the sidethereof, in admitting warmed air in relatively small quantities to saidinduction chamber and controlling the temperature of said warmed air andin injecting fuel at normal temperature into the Warm air stream at apoint adjacent to the induction chamber.

7. The method of conditioning fuel for internal combustion engines whichconsists in supplying a relatively larger quantity of air at normaltemperature to the induction chamber of the carburetor, in admittingwarmed air to the induction chamber in relatively small quantitiesthrough a separate passage, in controlling the temperature of the warmedair to compensate for the natural rise in the temperature. of airsurrounding the carburetor admitted through the secondary air passageand in injecting fuel at normal temperature into the warmed air streamat a point adjacent to the induction chamber.

8. The combination with a carburetor having a relatively small primaryair passage communicating with the induction chamber of the carburetorand a relatively'large secondary air passage communicating with saidchamber, means for injecting fuel to said primary air passage at a pointadjacent to the induction chamber and delivering directly into the sameat normal temperature and means for warming the air admitted throughsaid primary air passage an adjustable amount and at a point prior toits contact with the fuel admitted thereto. 9. The combination with acarburetor hav ing an induction chamber, a relatively small primary airpassage communicating directly with the induction chamber and arelatively large secondary air passage communicating with said chamberand for delivering atmospheric air thereto, a Vent-uri tube in theprimary air passage, means for injecting fuel to said primary airpassage around the throat portion of the Venturi tube at normaltemperature, and means for warming the air admitted through said primaryair passage at a point prior to its contact with the fuel admittedthereto, said last mentioned means including adjustable means forvarying the proportions of heated air and atmospheric air admittedthrough said primary passage.

1( The, combination with a carburetor hav ng an induction chamber, arelatively small primary air passage communicating directly with theinduction chamber and a relatively large secondary air passagecommunicating with said chamber and for dellvering atmospheric airthereto, a Venturi tube in the primary air passage, means for injectingfuel to said primary air passage around the throat portion of theVenturi tube at normal temperature, and means for warming the airadmitted through said primary air passage at a point prior to itscontact with the fuel admitted thereto, said means includmg a conduithaving an inlet end for the admission of air disposed so as to heat theair by the exhaust gases of a motor and having its opposite endcommunicating with the Venturi tube, and a valve interposed in saidconduit and having an inlet at one side communicating directly with theatmosphere and movable in an arc to close said inlet or simultaneouslyvary the proportion of heated air (zindt atmospheric air admitted intothe con- In witness whereof, I hereunto subscribe my name this 9th dayof August, 1927.

ROBERT F. BRACKE.

